executing "clear" only clears what is on the screen. The scrollback button will remain down at the bottom of the scrollbar if there were screenfulls of data previous to the screen just cleared. If you move the scroll bar button back up, the contents of the scrollback buffer will appear.

I think the original poster and I want to be able to clear the entire scrollback as well so that nothing remains lurking, this way one may output something to the screen and scroll back to the beginning of the output without worrying about scrolling into previous stuff.